Bone tamp and methods of use

ABSTRACT

A system comprises an inflatable bone tamp including a plurality of linearly aligned expandable bodies. The system further comprises an elongated tubular shaft extending through the plurality of linearly aligned expandable bodies. The elongated tubular shaft includes a shaft wall and an interior partition structure. The system further comprises a plurality of channels extending through the shaft, each of the channels formed by a segment of the shaft wall and the interior partition structure and each of the channels in communication with the respective one of the plurality of expandable bodies via openings in the shaft. Each of the expandable bodies is independently inflatable.

BACKGROUND

Bone loss is commonly associated with several diseases, includingosteolysis, metastatic lesions, and osteoporosis. Though bone loss oftenrefers to the dissolution of bone secondary to a variety of medicalconditions, the term osteolysis generally refers to a bone resorptionproblem common to artificial joint replacements such as hipreplacements, knee replacements, and shoulder replacements. Osteolysisoften occurs in the bone adjacent to an orthopedic implant, such as ahip or knee implant. As the body attempts to clean the orthopedicimplant wear particles from the surrounding bone, an autoimmune reactionmay be triggered. This autoimmune reaction causes the resorption ofliving bone tissue in addition to resorption of the wear particles. Thisbone resorption forms voids or osteolytic lesions in the bone.Osteolytic lesions are typically soft and spongy, and are unsupportiveof orthopedic implants. They may be amorphous and have indeterminateboundaries as viewed on radiographic images. An osteolytic lesion cancause a well-fixed implant to loosen. To treat osteolysis in the area ofan implant, it is often necessary to conduct a revision surgery in whichthe old implant is removed, the lesion is debrided, and a largerrevision implant is inserted.

In addition to osteolytic lesions secondary to implant reactions,another common form of osteolytic lesions are “punched out” osteolyticlesions secondary to metastatic cancer. “Punched-out” osteolytic lesionsare characteristic of metastatic lung and breast cancers and multiplemyeloma.

Both types of osteolytic lesions can trigger a host of serious medicalproblems in patients, including severe pain, bone fractures,life-threatening electrolyte imbalances, and nerve compressionsyndromes. One of the treatments for alleviating the symptoms ofosteolytic lesions involves clearing the lesion of cellular debris andfilling it with biomaterial or bone cement. Because patients withosteolytic lesions are typically older, and often suffer from variousother significant health complications, many of these individuals areunable to tolerate invasive surgery. Therefore, in an effort to moreeffectively and directly treat osteolytic lesions, minimally invasiveprocedures may be utilized to repair the bone by injecting anappropriate amount of flowable reinforcing material into the osteolyticlesion. Shortly after injection, the filling material hardens, therebyfilling the lesion and supporting the bone internally.

In contrast to an open procedure for the same purpose, a minimallyinvasive, percutaneous procedure will generally be less traumatic to thepatient and result in a reduced recovery period. However, minimallyinvasive procedures present numerous challenges. For example,conventional single balloon catheters used to compact bone and createcavities for reinforcing material are too small for use with the largerosteolytic lesions. Further, conventional single balloon catheters donot allow for versatile control of balloon inflation to accommodate theamorphous nature of osteolytic lesions. Accordingly, there exists a needfor instrumentation and techniques that facilitate the more effectiveand efficient treatment of bone dissolution using minimally invasiveprocedures.

SUMMARY

The present invention relates to devices and methods for cavity creationin bone with bone lesions, including osteolytic lesions and other areasof bone loss.

In one embodiment, a system comprises an inflatable bone tamp includinga plurality of linearly aligned expandable bodies. The system furthercomprises an elongated tubular shaft extending through the plurality oflinearly aligned expandable bodies. The elongated tubular shaft includesa shaft wall and an interior partition structure. The system furthercomprises a plurality of channels extending through the shaft, each ofthe channels formed by a segment of the shaft wall and the interiorpartition structure and each of the channels in communication with therespective one of the plurality of expandable bodies via openings in theshaft. Each of the expandable bodies is independently inflatable.

In another embodiment, a method of creating a cavity in a bone comprisesinserting, into a region of the bone with an osteolytic lesion, aninflatable bone tamp. The bone tamp includes a plurality of linearlyaligned expandable bodies and an elongated tubular shaft extendingthrough the plurality of expandable bodies. The elongated tubular shaftincludes a shaft wall and an interior partition structure. The methodfurther comprises injecting a first amount of inflation medium into afirst channel formed by a first segment of the shaft wall and theinterior partition structure to inflate a first one of the plurality ofexpandable bodies. The method further includes injecting a second amountof inflation medium into a second channel formed by a second segment ofthe shaft wall and the interior partition structure to inflate a secondone of the plurality of expandable bodies.

In another embodiment, a system comprises an inflatable bone tampincluding first, second, and third linearly aligned expandable bodies.The bone tamp has a length of at least 30 mm. The system furthercomprises an elongated tubular shaft extending through the first,second, and third expandable bodies. The elongated tubular shaft has aninner lumen and shaft wall. The system further includes first, second,and third channels extending through the shaft, each of the channels incommunication with the respective first, second, and third expandablebodies via openings in the shaft wall. Each of the expandable bodies isindependently inflatable.

Further aspects, forms, embodiments, objects, features, benefits, andadvantages of the present invention shall become apparent from thedetailed drawings and descriptions provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bone treatment system according to oneembodiment of this disclosure.

FIG. 2 is a detailed perspective view of a connecter assembly of theembodiment of FIG. 1.

FIGS. 3-5 are cross-sectional views of the proximal end of the bonetreatment system of FIG. 1.

FIG. 6 is a cross-sectional view of a bone treatment system according toanother embodiment of this disclosure.

FIG. 7 is a detailed perspective view of a connecter assembly accordingto another embodiment of this disclosure.

FIG. 8 is a cross-sectional view of a bone treatment system according toanother embodiment of this disclosure.

FIG. 9 is a view of the bone treatment system of FIG. 1 in use treatingan osteolytic lesion in an ilium.

FIGS. 10 and 11 are cross-sectional views of alternative embodiments forconnecting an expandable device to a shaft.

DETAILED DESCRIPTION

The present disclosure relates generally to the field of bone voidcreation, and more particularly to systems and methods for treating abone lesions, including osteolytic and metastatic lesions. For thepurposes of promoting an understanding of the principles of theinvention, reference will now be made to embodiments or examplesillustrated in the drawings, and specific language will be used todescribe these examples. It will nevertheless be understood that nolimitation of the scope of the invention is thereby intended. Anyalteration and further modifications in the described embodiments, andany further applications of the principles of the invention as describedherein, are contemplated as would normally occur to one skilled in theart to which the disclosure relates.

FIG. 1 is a perspective view of a bone treatment system 10 that can beused in a surgical procedure such as the treatment of an osteolyticlesion. The bone treatment system 10 includes an elongated shaft 12, abone tamp 14, and a connector system 16. The elongated shaft 12 is agenerally hollow, cylindrical tube with a proximal end 18 and a distalend 20. The elongated shaft 12 includes an outer wall 22 surrounding alumen 24. An axis 26 is defined by the elongated shaft 12. The shaft 12is comprised of a biocompatible material that is more resistant toexpansion than the material of the bone tamp 14. Further, the materialsfor the shaft may be selected to facilitate advancement of the bone tamp14. The shaft can be constructed, for example, using standard flexible,medical grade plastic materials, like vinyl, nylon, polyethylenes,ionomer, polyurethane, polyether block amide, and polyethylenetetraphthalate (PET). The shaft can also be fabricated from more rigidmaterials to impart greater stiffness and thereby aid in itsmanipulation. More rigid materials that can be used for this purposeinclude stainless steel, nickel-titanium alloys, and other metal alloys.

The bone tamp 14 includes a plurality of expandable bodies 28, 30, 32coupled to the distal end 20 of the shaft 12 and linearly aligned alongthe axis 26. The expandable bodies can be comprised of a flexible andbiocompatible material common in medical device applications, including,but not limited to, plastics, polyethelene, mylar, rubber, nylon,polyurethane, latex, metals or composite materials. For example, theexpandable body can be formed from a compliant (e.g., latex),semi-compliant (e.g., polyurethane), or non-compliant (e.g., nylon)material. The total length L of the bone tamp 14 is approximately 30 mm.It is understood that in alternative embodiments, the length of the bonetamp may be longer or shorter and the bone tamp may include fewer ormore expandable bodies. The size of the balloon tamp and the number ofconstituent expandable bodies may be chosen based upon the size andconfiguration of the bone lesion. In some embodiments, the size of theballoon tamp is larger than would be used for vertebral procedures suchas kyphoplasty. The expandable bodies may be spaced as close together aspossible along the shaft while still allowing for full inflation of thebodies. In alternative embodiments, the bodies may be spaced furtherapart. In alternative embodiments, the expandable bodies may beclustered, staggered, or may be spaced radially about the shaft.

In one embodiment, the outer expandable bodies 28, 32 may be formed of acompliant material and the central expandable body 30 may be formed of anon-compliant material. In an alternative embodiment, the centralexpandable body may be formed of a compliant material with the outerexpandable bodies formed of a non-compliant material. The size andnumber of expandable bodies may be selected based upon the size andconfiguration of the bone lesion in which the bone tamp will bedeployed.

The lumen 24 is configured to carry inflation media or cellularmaterial. As shown in the detailed perspective view of the proximal endof the elongated shaft of FIG. 2 and in the cross-sectional views of theproximal end of the elongated shaft of FIGS. 3-5, the lumen 24 ispartitioned so that different sections of the lumen can be used fordifferent purposes. In this embodiment, a Y-shaped partition structure34 extends through the shaft 12 within the lumen 24. The partitionstructure 34 divides the lumen 24 into three channels 36, 38, and 40.Each of the channels 36, 38, 40 is defined by a segment of the outerwall 22 and the partition structure 34. Each of the channels 36, 38, 40has a proximal opening near the proximal end 18 of the elongated shaft12 and a distal opening near the distal end 20 of the elongated shaft12. Specifically, as shown in FIG. 3, channel 38 has a proximal opening42 and a distal opening 44. The distal opening 44 extends through theouter wall 22 of the shaft 12 in a region of the shaft around which theexpandable body 32 is coupled. Thus, a flow channel from the proximalopening 42 into the expandable body 32 is created by the channel 38.Similarly, as shown in FIG. 4, channel 36 has a proximal opening 46 anda distal opening 48. The distal opening 48 extends through the outerwall 22 of the shaft 12 in a region of the shaft around which theexpandable body 30 is coupled. Thus, a flow channel from the proximalopening 46 into the expandable body 30 is created by the channel 36.Similarly, as shown in FIG. 5, channel 40 has a proximal opening 50 anda distal opening 52. The distal opening 52 extends through the outerwall 22 of the shaft 12 in a region of the shaft around which theexpandable body 28 is coupled. Thus, a flow channel from the proximalopening 50 into the expandable body 28 is created by the channel 40.

Although the proximal openings are depicted as generally circular andthe distal openings are depicted as generally elongated slots, it isunderstood that any shape or size of opening in the outer wall 22 may besuitable. Further, the invention is not limited to single proximal anddistal openings for each of the channels, rather multiple openingthrough the outer wall 22 may be suitable. In alternative embodiments, apartition may divide the lumen into fewer or more than three channels.For example, if the bone tamp 14 comprised four expandable bodies, apartition structure may divide the lumen of the shaft into fourchannels. Alternatively, a partition structure may divide the lumen intofour channels with three of the four channels used to create flowchannels between proximal openings and a respective expandable body andthe fourth channel used to provide a flow channel for aspiration and/orsuction. In other alternative embodiments, a radio-frequency instrumentmay be deployed through one of the channels for ablation of theosteolytic lesion.

In an alternative embodiment, as shown in FIG. 6, an elongated shaft 60which is substantially similar to elongated shaft 12 has a lumen 61through which a plurality of channels 62 extend. Each of the channels 62is formed by a separate elongated tube, which serves as a partition, andextends between a proximal opening in the shaft 60 to a distal openingin the shaft within a region surrounded by a respective expandable body.It is understood that other partition structures for dividing the lumenof the shaft into channels may be used.

Referring again to FIGS. 1 and 2, the connector system 16 is coupled tothe proximal end 18 of the shaft 12. In this embodiment, the connectorsystem 16 includes a connector 66 in communication with the proximalopening 42, a connector 68 in communication with the proximal opening46, and a connector 70 in communication with the proximal opening 50.Each of the connectors 66, 68, 70 thus allow each of the respectiveexpandable devices 32, 30, 28 to be independently inflated. As depicted,each of the connectors can be a Luer lock connector, but can also beconfigured in a wide variety of other connector options. For example,the connectors may be configured as a hose barb or a slip fit connector.The connectors 66, 68, 70 are used for receiving inflation material(e.g., saline solution or contrast solution) for inflating theexpandable bodies. In alternative embodiments, connectors may also beused for withdrawing cellular matter from an osteolytic lesion and fordelivering flowable reinforcement materials, such as bone cement, intothe lesion. The connectors 66, 68, 70 provide for the releasableconnection of the bone treatment system 10 to a source of flowablematerial.

As shown in FIG. 9, a percutaneous method for using the bone treatmentsystem 10 in a portion of a human hip will be described. An acetabularjoint 110 includes an ilium 112 and the head 114 of a femur. Within theilium 112, a bone lesion 116 has a multi-loculated area of bone loss. Itis understood that the systems and methods herein described may be usedto treat lesions in other bones such as the femur or the calcaneous.

In this embodiment, the method of use includes inserting a cannula 118into the ilium 112. In this embodiment, the cannula 118 is an elongated,hollow, cylindrical tube with a lumen 120. The cannula is comprised of astrong, non-reactive, medical grade material, such as stainless steel.In alternative embodiments, the cannula may he any type and size ofhollow insertion instrument and may be made from metals or plastics.

The cannula 118 is positioned at an exterior surface of the ilium 112 orshallowly inserted into the ilium using a guide needle and/or dissector.After the cannula 118 is positioned, a drill or other access tool can beused to create a passage 121 through the ilium to the hone lesion 116.The bone tamp 14 carried by the shaft 12 is inserted through the cannula118, through the passage 121 and into the bone lesion 116. Thepositioning of the bone tamp and shaft within the bone lesion 116 may bevisualized by the physician using visual imaging monitoring techniquessuch as fluoroscopy. Therefore, in some embodiments, radiopaque markerscan be placed at various locations on the bone tamp 14 to facilitateappropriate placement of the bone tamp within the lesion. In otherembodiments, the bone tamp 14 may be formed from or can includeradiopaque materials. In still other embodiments, the bone tamp 14 orthe shaft 12 can include visible indicia such as a marker visible byother imaging modalities such as ultrasound, computed tomography (CT),or magnetic resonance imaging (MRI). In some alternative embodiments,the cannula may be omitted and the bone treatment system 10 may beinserted directly into the bone lesion.

Once the bone tamp 14 is in position, the expandable bodies 28, 30, 32are independently inflated to compress the walls of the osteolyticlesion 116. Specifically, an inflation medium is conveyed by a fluiddispensing device, such as a syringe, through the connector 66, into theproximal opening 42, through the channel 38 and into the expandable body32 via the opening 44. The inflation medium causes the expandable body32 to inflate. Next, using the same or a different fluid dispensingdevice, an inflation medium is conveyed through the connector 68, intothe proximal opening 46, through the channel 36 and into the expandablebody 30 via the opening 48. The inflation medium causes the expandablebody 30 to inflate.. Next, an inflation medium is conveyed through theconnector 70, into the proximal opening 50, through the channel 40 andinto the expandable body 28 via the opening 52. The inflation mediumcauses the expandable body 28 to inflate.

The inflation of the expandable bodies causes the surrounding cancellousbone and cellular tissue to become displaced generally outward from theexpandable bodies in a controlled manner, forming a compressed boneregion or shell. The inflation of the expandable bodies may be monitoredfluoroscopically by using radiopaque markers or by using a radiopaqueinflation medium. Monitoring allows the physician to selectively andindividually inflate the expandable bodies to form an overall bone tamplength and configuration unique to the size and shape of the osteolyticlesion. Because each of the expandable bodies is independentlyinflatable, the overall shape, size, and configuration of the bone tamp14 can be individually tailored to for each patient's particularosteolytic lesion. As compared to bone tamps with a single smallerballoon that may require multiple deployments and therefore additionaltime to fully compress the boundary of the osteolytic lesion, the largersize and versatility of the bone tamp 14 may allow for a singledeployment to accomplish the desired bone compression.

It is understood that the provided sequence for inflating the expandablebodies is merely an example and in alternative embodiments theexpandable bodies can be inflated in other sequences. For example, insome embodiments it may be desirable to inflate the center expandablebody before inflating the outer expandable bodies. Alternatively, it maybe desirable to inflate the outer expandable bodies before inflating thecenter body.

After the shell of compressed bone and other tissue is formed, theinflation medium may be removed from the expandable bodies 28, 30, 32via the connectors 50, 46, 42, respectively using a fluid suction devicesuch as a syringe. In some embodiments, the inflation medium from oneexpandable body may be removed before another of the expandable bodiesis inflated.

With the expandable bodies 28, 30, 32 deflated, the bone tamp 14 andshaft 12 are withdrawn from the bone through the cannula 118. A flowablebone reinforcement material that sets to a hardened condition, such asbone cement, is injected into the expanded bone lesion 116 and allowedto set to a hardened condition. The shell of compressed bone around thelesion 116 may serve to prevent extravasation of reinforcement materialfrom the bone lesion. The hardened bone filler provides structuralsupport for the bone of the ilium 112 surrounding the bone lesion 116,thereby substantially restoring the structural integrity of the hip. Theflowable material can be introduced into the bone lesion by a type ofmaterial delivery system known in the art. Suitable flowablereinforcement materials may include graft material or polymer compounds.For example, polymethyl methacrylate (PMMA) compositions such as KYPHONHV-R® Bone Cement or compositions that contain PMMA and hydroxyapatite(HA) such as KYPHON ActivOs™ 10 bone cement offered by Medtronic, Inc.of Minneapolis, Minn. may be suitable.

In the embodiment of FIGS. 1 and 2, the connector system 16 has aseparate connector associated with each proximal opening and itscorresponding channel through the shaft. In alternative embodiments, forexample as shown in FIGS. 7 and 8, a single connector is switchablebetween multiple positions for connecting to different proximal openingsto channels within a shaft.

For example, as shown in FIG. 7, a connector system 70 is coupled to anelongated shaft 72. Like the elongated shafts previously described, theelongated shaft 72 has a lumen with a plurality of channels extendingtherethrough. Each of three channels in the shaft 72 has a respectiveproximal opening 74, 76, 78 through the wall of the shaft 72. In thisembodiment, the proximal openings are linearly aligned, but otherarrangements for the proximal openings may be suitable. The connectorsystem 70 includes a connector 80 and a sleeve member 82. The sleevemember 82 is slidably coupled to the shaft 72. The connector system 70is switchable between a first position in which the connector 80 is incommunication with the proximal opening 74, a second position in whichthe connector 80 is in communication with the proximal opening 76, and athird position in which the connector 80 is in communication with theproximal opening 78. To switch between the first, second, and thirdpositions, the connector system 70 is moved axially along the shaft 72between the various positions. When the connector 80 is in the firstposition in communication with the proximal opening 74, the sleevemember 82 seals the openings 76, 78 against inflow of material injectedthrough the connector 80. The connector system 70 may further include acontroller (not shown) such as a handle or grip for moving the connectorsystem between positions. Other suitable controllers include rotatableknobs, slider switches, pull tabs, linear actuators, compression grips,and triggers. The controllers may move the connector between multiplepreset stops corresponding to the location of the proximal openings.

In another embodiment, as shown in FIG. 8, a connector system 90 iscoupled to an elongated shaft 92. Like the elongated shafts previouslydescribed, the elongated shaft 92 has a lumen with a plurality ofchannels 94, 96, 98 extending therethrough. Each of channels 94, 96, 98has a respective proximal opening 99, 100, 102. In this embodiment, theproximal openings are distributed radially around the shaft 92. Theconnector system 90 includes a connector 104 and a sleeve member 106.The sleeve member 106 is rotatably coupled to the shaft 92. Theconnector system 90 is switchable between a first position in which theconnector 104 is in communication with the proximal opening 99, a secondposition in which the connector 104 is in communication with theproximal opening 100, and a third position in which the connector 104 isin communication with the proximal opening 102. To switch between thefirst, second, and third positions, the connector system 90 is rotatedabout the shaft 92 between the various positions. When the connector 104is in the second position in communication with the proximal opening100, the sleeve member 106 seals the openings 99, 102 against inflow ofmaterial injected through the connector 104. The connector system 90 mayfurther include a controller (not shown) such as a handle or grip formoving the connector system between positions. Other suitablecontrollers include rotatable knobs, slider switches, pull tabs, linearactuators, compression grips, and triggers. The controllers may move theconnector between multiple preset stops corresponding to the location ofthe proximal openings.

The expandable bodies described above may be connected to the shaft inany of several alternative ways. As shown in FIG. 10, an expandable body130 includes an expandable region 131 and end portions 132. The endportions 132 extend away from the expandable region 131 and may beattached to a shaft 134 by a heat bond, an adhesive, or a bondingstructure 136 such as a collar or a heat shrinkable tubing. As shown inFIG. 11, an expandable body 140 includes an expandable region 141 andend portions 142. The end portions 142 turn inward toward the expandableregion and are affixed to a shaft 144 by a heat bond, an adhesive, orany other known bonding technique. The underturned configuration of FIG.11 may be a particularly beneficial construction for the bone tamp 14because space along the shaft is not utilized for adhesion of theexpandable bodies. With this embodiment, the expandable bodies may bepositioned more closely together, and void creation may be morecontinuous. Further, the underturned configuration may allow anexpandable body to be located at a distal most end of the shaft withoutneed to reserve space along the shaft, distal of the expandable body,for attachment of the expandable body to the shaft. The underturnedconfiguration may also assist with removal of the expandable bodiesafter deflation.

While the present invention has been illustrated by the abovedescription of embodiments, and while the embodiments have beendescribed in some detail, it is not the intention of the applicant torestrict or in any way limit the scope of the invention to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, representative apparatus andmethods, and illustrative examples shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of the applicant's general or inventive concept. In theclaims, means-plus-function clauses are intended to cover the structuresdescribed herein as performing the recited function and not onlystructural equivalents, but also equivalent structures.

1. A system comprising: an inflatable bone tamp including a plurality oflinearly aligned expandable bodies; an elongated tubular shaft extendingthrough the plurality of linearly aligned expandable bodies, theelongated tubular shaft including a shaft wall and an interior partitionstructure; a plurality of channels extending through the shaft, each ofthe channels formed by a segment of the shaft wall and the interiorpartition structure and each of the channels in communication with therespective one of the plurality of expandable bodies via openings in theshaft, wherein each of the expandable bodies is independentlyinflatable.
 2. The system of claim 1 further comprising a plurality ofinflation ports, each in communication with a respective channel.
 3. Thesystem of claim 2 further comprising a respective inflation connectorcoupled to each inflation port.
 4. The system of claim 2 furthercomprising an inflation connector configured to couple to one of theinflation ports in response to the position of a switch mechanism. 5.The system of claim 1 wherein the interior partition structure has aY-shaped cross-section.
 6. The system of claim 1 wherein the pluralityof linearly aligned expandable bodies includes first, second, and thirdlinearly aligned expandable bodies.
 7. The system of claim 6 wherein thesecond expandable body is formed of a different material than the firstand third expandable bodies.
 8. The system of claim 6 wherein the secondexpandable body is formed of a non-compliant material.
 9. The system ofclaim 6 wherein the second expandable body is formed of a compliantmaterial.
 10. A method of creating a cavity in a bone, the methodcomprising: inserting, into a region of the bone with a lesion, aninflatable bone tamp, including a plurality of linearly alignedexpandable bodies and an elongated tubular shaft extending through theplurality of expandable bodies, wherein the elongated tubular shaftincluding a shaft wall and an interior partition structure; injecting afirst amount of inflation medium into a first channel formed by a firstsegment of the shaft wall and the interior partition structure toinflate a first one of the plurality of expandable bodies; and injectinga second amount of inflation medium into a second channel formed by asecond segment of the shaft wall and the interior partition structure toinflate a second one of the plurality of expandable bodies.
 11. Themethod of claim 10 further comprising: compacting a first portion of thebone with the first one of the expandable bodies and compacting a secondportion of the bone with the second one of the expandable bodies. 12.The method of claim 11 further comprising: inserting a filling materialthat sets to a hardened condition into the compacted first and secondportion of the bone.
 13. The method of claim 10 further comprising:injecting a third amount of inflation medium into a third channel formedby a third segment of the shaft wall and the interior partitionstructure to inflate the third expandable body.
 14. The method of claim10 wherein the inflatable bone tamp has a length of at least 30 mm. 15.The method of claim 10 wherein the bone is an ilium.
 16. The method ofclaim 10 wherein the step of injecting a first amount of inflationmedium includes injecting a first amount of inflation medium through aconnector coupled to a port in the first channel.
 17. The method ofclaim 16 further comprising switching the connector to couple to a portin the second channel for injecting the second amount of inflationmedium.
 18. A system comprising: an inflatable bone tamp includingfirst, second, and third linearly aligned expandable bodies, the bonetamp having a length of at least 30 mm; an elongated tubular shaftextending through the first, second, and third expandable bodies, theelongated tubular shaft having an inner lumen and shaft wall; and first,second, and third channels extending through the shaft, each of thechannels in communication with the respective first, second, and thirdexpandable bodies via openings in the shaft wall, wherein each of theexpandable bodies is independently inflatable.
 19. The system of claim18 further comprising a partition structure extending within the innerlumen, wherein each of the channels is formed by a segment of the shaftwall and the partition structure.
 20. The system of claim 18 whereineach of the channels includes a tube having a circular cross-section.